Pseudoscience and Bias: The Influence of Physiognomy and Craniology on Modern Healthcare

by Amisha Reddy


From the author

This project examines the development of pseudoscientific disciplines such as physiognomy, craniometry, phrenology, and racial anatomy and analyzes how they continue to influence modern healthcare systems. Although these fields are now formally rejected as pseudosciences, I became interested in how many of the ideas they promoted — particularly beliefs surrounding racial biological differences and gendered “inferiority” or “primitiveness” — still appear in modern medicine. The project specifically focuses on how eighteenth and nineteenth century scientists attempted to classify human populations through so-called objective anatomical measurements, facial analysis, and racial categorization. Scientists such as Carl Linnaeus, Johann Lavater, Cesare Lombroso, Samuel George Morton, and Georges Cuvier all contributed to systems that framed racial and gender hierarchies as natural and scientifically measurable, reinforcing their harmful ideologies. Part of the goal of this paper was to examine how scientific authority often depends upon existing cultural and societal prejudices rather than neutral observation despite claims and assumptions of objectivity. 
 
Connecting it back to this class, I wanted to examine how women, specifically Black women and women of color and women associated with prostitution, became major targets of these pseudoscientific frameworks. While researching, I found it striking how many modern medical disparities reflect assumptions that closely resemble older racialized beliefs about the body. The paper therefore takes the time to examine modern examples such as racial bias in pain assessment and treatment, unequal representation of darker skin in medical education and dermatology resources, and algorithmic bias within healthcare technologies. Reiterating the theme of false objectivity, I was particularly interested in exploring how technologies and medical systems often appear data-driven and formulaic, but still reproducing the same historical inequalities through biased datasets, cultural assumptions, or unequal representation. One aspect of this project that especially stood out to me was the conflict between preserving historical scientific texts and critically engaging with them. For example, while researching Lavater’s Essays on Physiognomy, I noticed that some modern descriptions of the text labeled it as “culturally important” and part of the “knowledge base of civilization.” Although I do understand how preserving historical documents is valuable for understanding the development of scientific thought, I found it rather abominable how casually such harmful and discriminatory ideas are framed as a neutral intellectual history that is important for society without acknowledging the very real harm they caused. This realization truly reinforced one of the central arguments of my paper in that scientific knowledge is never fully separate from the cultural and political systems in which it is produced.

Science and medicine are often associated with objectivity, empirical observations, and neutrality, and scientific authority has often been based on the belief that biological evidence can reveal universal truths about the human body independent of social or cultural influence. However, the history of science demonstrates how scientific interpretations of the body tend to reflect the powers and prejudices of the time rather than purely objective observations. During the eighteenth and nineteenth centuries, European scientists and physicians increasingly attempted to classify human difference through anatomical measurement, visual analysis, and biological categorization, including fields such as physiognomy, craniometry, and racial anatomy. These disciplines claimed that moral character, intelligence, sexuality, and social deviance could be identified through physical features of the face and body. Although they presented themselves as objective sciences,they relied heavily on harmful cultural biases about race, gender, sexuality, and morality.

Historians and philosophers of science generally define pseudoscience as systems of belief that claim scientific legitimacy while lacking true reliable empirical evidence or methodology. Although physiognomy and racial anatomy were widely accepted in parts of the nineteenth century, they are now recognized as pseudoscientific because their conclusions were based on social prejudice rather than any verifiable biological facts. These disciplines transformed existing fears and stereotypes into supposedly objective medical truths, particularly through the characterization of non-European women and prostitutes as naturally immoral, hypersexual, contagious, or intellectually inferior.

While these pseudoscientific fields have been officially and formally discredited, many of the assumptions they helped establish continue to shape modern medicine as contemporary healthcare systems still reveal historical beliefs about biological racial differences, especially in areas such as pain perception, medical education, and diagnostic technologies such as algorithms. Studies such as the 2016 research conducted by Kelly Hoffman have shown that false assumptions about Black patients’ pain tolerance continue to influence treatment decisions, while medical textbooks and healthcare technologies frequently prioritize white bodies as the medical norm, making certain conditions more difficult to identify on darker skin (Hoffman, 2016). Although modern medicine no longer openly endorses physiognomy or racial anatomy, the persistence of these biases demonstrates how scientific authority has never been fully separate from cultural and social power. This paper aims to examine the historical development of pseudoscientific ideas alongside their modern medical consequences.

During the eighteenth and nineteenth centuries, European science became increasingly focused on the classification and categorization of the natural world, including human populations. Enlightenment scientists aimed to organize nature into systems that appeared “rational”, and human beings, especially non-European races, increasingly became subjects of biological classification. As scientific authority became more closely associated with observations and measurements, many scientists and physicians began to argue that visible physical differences between people could supposedly reveal biological differences in morality, intelligence, temperament, and behavior.

One important example of this shift can be seen in the work of Carl Linnaeus, whose Systema Naturae, categorized human beings into racial groups. Within this system, Linnaeus divided humanity into classifications such as Homo Europaeus, Homo Afer, and Homo Asiaticus, assigning each category not only physical descriptions, but also moral and behavioral characteristics. Europeans, for example, were often associated with rationality and intelligence, while non-European populations were described through stereotypes portraying them as irrational, lazy, or emotionally and physically excessive (Linnaeus 1964). These ideas encouraged the belief that race was scientifically measurable and an indicator of superiority or inferiority. These classifications contributed to a broader trend in which scientists and physicians increasingly treated physical features as objective evidence of intellectual, moral, and social worth.

At the same time, more “precise” anatomical measurements became central to many emerging scientific disciplines. For example, craniometry and phrenology attempted to measure skull size, facial features and angles, and cranial structure in order to determine intelligence and personality. Although these fields presented themselves as empirical sciences, their conclusions were based off of and only served to reinforce existing colonial and patriarchal assumptions. European bodies were always shown as the standards of intelligence and “proper” civilization, while colonized populations, especially Black populations, were described as primitive, irrational, and biologically inferior (National Human Genome Research Institute, 2022).

The authority granted to anatomical observation also shapes ideas about gender with women’s bodies being interpreted through assumptions about emotional instability, reproductive weakness, and intellectual inferiority dating back to the “wandering womb” theory (Tasca et al. 2012). Physicians argued that women’s biological structures, such as the presence of an uterus, made them less rational and more emotionally governed than men as prominently demonstrated by the coining of the term hysteria. As shown by the aforementioned, scientific discussions of the body did not just describe physical differences in the “objective” way they claimed to; instead they translated social hierarchies into “empirical” biological markers.

As mentioned prior, physiognomy became one of the most influential examples of this process. Physiognomy claimed that facial features, such as forehead size, could reveal inherent moral and psychological traits. The discipline transformed subjective judgments about appearance into supposedly objective scientific conclusions, centering white populations and appearances. One of the major figures associated with physiognomy was Johann Lavater, who argued that the structure of the face reflected inner moral character (Maxwell, 2026). According to physiognomic theory developed in his book Essays on Physiognomy, virtue, criminality, intelligence, and emotional disposition could supposedly be read directly from a person’s appearance (Johann Caspar Lavater  and Holcroft 1806). 

The continued preservation and circulation of texts such as Lavater’s Essays on Physiognomy also demonstrates how pseudoscientific ideas remain embedded within cultural and academic history. Straying from the discussion a slight, when I was searching for his essay, I stumbled upon its google description, with it being called “culturally important” and part of the “knowledge base of civilization,” language that is rather unsettling given that the work promoted deeply racist and discriminatory assumptions disguised as science. While preserving historical documents is important for understanding the development of scientific thought, the continued framing of such works as universally valuable without critical context risks minimizing the harm these theories caused to non-European populations and other marginalized groups.

These theories were deeply racialized as building off of the prejudices of the time, European facial features were associated with rationality, refinement, restraint, and moral superiority, while the features of non-European populations were described as animalistic, impulsive, primitive, or excessively emotional (National Human Genome Research Institute, 2022). For example, Africans were often portrayed in physiognomic and racial anatomical texts as naturally driven by instinct rather than reason, a characterization used to justify colonial domination and slavery. Rather than objectively studying the body as its supporters claimed, physiognomy projected existing colonial ideologies onto the body and then presented those prejudices as a scientific truth. 

Women were also interpreted through such bigoted physiognomic frameworks. Female facial features were frequently linked to assumptions about emotional instability, sexual excess, and moral weakness. Prostitutes in particular were often portrayed as visibly distinguishable through supposedly deviant physical traits, including exaggerated facial expressions, “coarse” features, or signs of bodily degeneration (“Promising Future, Complex Past: Artificial Intelligence and the Legacy of Physiognomy,” n.d.). The work of Cesare Lombroso demonstrates how these ideas became integrated into criminology and medicine. In The Female Offender, Lombroso argued that criminal women and prostitutes possessed identifiable anatomical abnormalities that reflected innate moral degeneracy. He described criminal women as having asymmetrical faces, large jaws, thick lips, and masculine features that supposedly indicated biological inferiority and deviant sexuality (Lombroso, 1895). Lombroso treated prostitution not as a social or economic condition caused by the state of society, but as evidence of hereditary degeneration. These ideas were especially harmful because they framed social marginalization as biological inevitability and served to further separate classes. Poverty, exploitation, and limited economic opportunities were ignored in favor of biological explanations, allowing social prejudice to appear scientifically justified.

Racial anatomy similarly used bodily differences to reinforce racial hierarchies. During the nineteenth century, scientists increasingly attempted to establish racial “rankings” through anatomical measurement and comparison, with the Eurocentric body naturally positioned as the apex of the hierarchy. One major figure associated with these efforts was Samuel George Morton who collected and measured hundreds of human skulls in order to correlate intelligence and cranial size (Gould, 1978). Morton argued that Europeans possessed the largest cranial volumes, Africans the smallest, and Native Americans somewhere in between, showing how Africans were the most “inferior” of the races. These conclusions aligned closely with existing racial hierarchies and colonial assumptions, becoming widely accepted by the general populace. Although Morton presented his research as objective, standardized science, historians have shown that his measurements and interpretations were shaped by confirmation bias and the dominant cultural views of the time (Gould, 1978). By using a scientific language of measurement and quantification, he gave racial hierarchy an appearance of neutrality and factual certainty when in reality, these studies relied on the assumption that social dominance (if you can call it that) reflected natural  biological superiority in the first place.

Similar to physiognomy, scientific discussions of women often overlapped heavily with racial hierarchies. Black women in particular became targets of racialized anatomical study and were frequently portrayed as hypersexual, infectious, physically excessive, and morally deviant (National Human Genome Research Institute, 2022). One prominent example of this is Sarah Baartman, a Khoikhoi woman from South Africa who was exhibited in Europe during the early nineteenth century under the name “Hottentot Venus.” After her death, anatomist Georges Cuvier studied and dissected her body, focusing particularly on her buttocks, hips, and genitalia, which he presented as evidence of primitive sexuality and racial inferiority (The Comparative Anatomy of “Hottentot” Women in Europe, 1995). European scientists interpreted these characteristics as signs of uncontrollable sexual desire and abnormality, reinforcing the belief that Black women existed closer to “nature” and farther from European standards of civilization and restraint. Baartman’s body became a way for European scientists to project their fantasies about race, sexuality, and colonial differences, demonstrating how scientific authority often depended on dehumanization. Rather than recognizing her individuality or humanity, scientists interpreted her body through preexisting assumptions about Black female “hypersexuality,” reinforcing colonial ideas that non-European women were naturally promiscuous and physically excessive.

One thing of note was that pseudoscientific ideas about racial and sexual deviance did not remain confined to academic theory. They strongly influenced public health policy and medical institutions. For instance, fueled by pseudosciences, fears surrounding contagious diseases led governments to increase surveillance over women associated with prostitution because they were viewed as sources of moral impurity, sexual disorder, and biological contamination (Knox, 2022). It was rather frequent that public health policies portrayed female sexuality as a biological threat requiring medical regulation. Another example is the Contagious Diseases Acts in Britain (Knox, 2022). These laws allowed police officers to detain women suspected of prostitution and subject them to compulsory genital examinations. These suspicions were often based on arbitrary judgments about a woman’s appearance, class, or presence in certain public spaces, meaning that poor and working class women were disproportionately targeted. Women diagnosed with infection could then be forcibly confined, where they endured social stigma, loss of employment if they worked, and severe restrictions on autonomy. Men, however, were not subjected to equivalent forms of surveillance or punishment, demonstrating how public health policies reinforced gendered hierarchies where women were blamed for sexual diseases while male behavior remained largely unregulated. In this way, women’s bodies became sites of institutional control in the excuse of medicine and public safety.

Although physiognomy, craniometry, and racial anatomy are now officially rejected as pseudosciences, many of their assumptions continue to shape contemporary medicine. Modern healthcare systems tend to reproduce beliefs about biological racial difference even while claiming scientific neutrality. One of the most famous examples can be seen in racial disparities surrounding pain perception and treatment. Hoffman’s study has shown that Black patients are less likely to receive adequate pain treatment than white patients (Hoffman, 2016). Additionally, her studies have found that healthcare providers often underestimate the severity of Black patients’ pain and are less likely to prescribe pain medication as they believe myths that Black people have thicker skin, less sensitive nerve endings, or greater tolerance for pain. 

Earlier pseudoscientific theories similarly claimed that Black bodies were biologically different in ways that justified unequal treatment. Although modern medicine no longer openly describes Black patients as biologically inferior, remnants of these assumptions continue to persist through clinical practice and medical training. The studies on pain bias demonstrate how historical ideas can survive even after their original scientific frameworks have been rejected. Medical students are not formally taught physiognomy or craniometry, yet older cultural narratives about racialized bodily differences still shape perceptions of pain and physical vulnerability.  

Pseudoscientific ideas also continue to influence medical education itself, as shown by how medical textbooks and teaching materials have historically prioritized white bodies as the standard representation of health and disease (Louie and Wilkes 2018), leading to something aptly termed white skin bias. Dermatology provides one particularly visible example as many dermatological conditions — such as rashes, cyanosis, and skin cancer — present differently on darker skin tones, yet medical textbooks focus on lighter skin (Louie and Wilkes 2018). A study by Ebede and Papier found that the coverage of dark skin in images in major dermatology resources ranged from 4% to 18% (Ebede & Papier, 2006). Similarly, Patricia Louie and Rima Wilkes, in their study Representations of Race and Skin Tone in Medical Textbook Imagery, analyzed 4,146 images from widely used medical textbooks, including Gray’s Anatomy for Students and Bates’ Guide to Physical Examination and History Taking. Although the textbooks appeared to reflect the overall racial demographics of the United States population, the researchers found that skin tone representation remained overwhelmingly skewed toward lighter skin. Specifically, 74.5% of the images depicted light skin tones, while only 4.5% represented dark skin tones (Louie & Wilkes, 2018). The study also found that racial minorities and darker skin tones were frequently absent at the chapter and topic level, showing how even when diversity exists, it was often excluded from discussions of specific diseases or medical conditions. Louie and Wilkes argue that these omissions help normalize white skin as the default medical standard and may contribute to racial disparities in healthcare treatment and diagnosis.

More recent studies suggest that these disparities continue within contemporary medical education. For example, the study Addressing Visual Learning Equity in Undergraduate Dermatology Education: Skin Color Representation Across Dermatology Lecture Images at Rutgers New Jersey Medical School examined dermatology lecture slides used in pre-clerkship medical education. Researchers found that 59.5% of the images depicted light or white skin, while only 24.4% represented dark or Black skin tones (Janodia et al., 2025). The underrepresentation of darker skin in educational materials limits students’ exposure to how medical conditions present across different populations and reinforces the assumption that white bodies represent the medical norm. These patterns demonstrate that although explicit forms of scientific racism such as physiognomy and racial anatomy have been formally rejected, their underlying assumptions continue to shape modern medical knowledge, education, and clinical practice.

Another significant example can be seen in pulse oximeters have been shown to produce less accurate readings in patients with darker skin tones because the technology was insufficiently tested across diverse populations (Winny and Jurmo, 2024). During the COVID-19 pandemic, researchers found that Black patients were more likely to experience occult hypoxemia that the devices failed to detect accurately. The unequal design of medical technologies and educational resources reveals how the legacy of scientific racism continues to shape healthcare outcomes.

As implied earlier, this issue extends into modern healthcare technologies and algorithms. With advancing technology, medical systems increasingly rely on predictive algorithms, artificial intelligence, and data from healthcare datasets to guide clinical decisions. These technologies are often presented as objective and unbiased because they depend on data analysis rather than individual human judgment; however, algorithms can reproduce historical inequalities when they are trained on biased or incomplete data. One major study by Obermeyer in 2019 examining healthcare algorithms found that an algorithm used to determine patient healthcare needs systematically underestimated the medical needs of Black patients. The algorithm used healthcare spending as a measurement for health, but failed to account for the fact that Black patients historically receive less access to healthcare resources. As a result, Black patients were less likely to be identified for additional medical care even when they were equally sick. This example demonstrates how modern technology does not automatically eliminate social bias as we like to believe it does. Instead, healthcare algorithms can reproduce existing inequalities while appearing scientifically neutral and mathematically objective. 

Something to note is that recognizing these problems does not mean rejecting science or medicine entirely. I believe that the problem is not that scientific inquiry itself is inherently oppressive, but that scientific institutions are shaped by the societies in which they operate and not enough precautions are taken to reduce societal and cultural bias. These pseudoscientific disciplines of physiognomy and racial anatomy did more than just misinterpret biological evidence; they transformed cultural prejudices into scientific authority by presenting racial and sexual stereotypes as objective medical truths. These ideas legitimized discrimination within medicine, public health policy, and scientific institutions, particularly against racially marginalized women and women labeled sexually deviant. Although these disciplines have formally been rejected, their influence continues to shape contemporary healthcare inequalities. False beliefs about racial biological differences remain visible in pain treatment disparities, medical education, diagnostic representation, and healthcare algorithms. The persistence of these biases demonstrates how scientific knowledge is never produced in complete isolation from society despite that being a common assumption. Social values, political power, and cultural assumptions all influence how bodies are studied, categorized, and treated. Recognizing the origins of these scientific inequalities is important for building a more equitable medical system that truly treats everyone without discrimination. 

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